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William F. Egan
William F. Egan (1936 – 2018) was well-known expert and author in the area of PLLs. The first and second editions of his book ''Frequency Synthesis by Phase Lock'' as well as his book ''Phase-Lock Basics'' are references among electrical engineers specializing in areas involving PLLs. Egan's conjecture on the pull-in range of type II APLL In 1981, describing the high-order PLL, William Egan conjectured that type II APLL has theoretically infinite the hold-in and pull-in ranges. From a mathematical point of view, that means that the loss of global stability in type II APLL is caused by the birth of self-excited oscillations and not hidden oscillations (i.e., the boundary of global stability and the pull-in range in the space of parameters is trivial). The conjecture can be found in various later publications, see e.g. and for type II CP-PLL. The hold-in and pull-in ranges of type II APLL for a given parameters may be either (theoretically) infinite or empty, thus, since t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase-locked Loop
A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a variable frequency oscillator and a phase detector in a feedback loop. The oscillator's frequency and phase are controlled proportionally by an applied voltage, hence the term voltage-controlled oscillator (VCO). The oscillator generates a periodic signal of a specific frequency, and the phase detector compares the phase of that signal with the phase of the input periodic signal, to adjust the oscillator to keep the phases matched. Keeping the input and output phase in lockstep also implies keeping the input and output frequencies the same. Consequently, in addition to synchronizing signals, a phase-locked loop can track an input frequency, or it can generate a frequency that is a multiple of the input frequency. These properties are use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Engineers
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the latter half of the 19th century after commercialization of the electric telegraph, the telephone, and electrical power generation, distribution, and use. Electrical engineering is now divided into a wide range of different fields, including computer engineering, systems engineering, power engineering, telecommunications, radio-frequency engineering, signal processing, instrumentation, photovoltaic cells, electronics, and optics and photonics. Many of these disciplines overlap with other engineering branches, spanning a huge number of specializations including hardware engineering, power electronics, electromagnetics and waves, microwave engineering, nanotechnology, electrochemistry, renewable energies, mechatronics/control, and electrical m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase-locked Loop Range
The terms hold-in range, pull-in range (acquisition range), and lock-in range are widely used by engineers for the concepts of frequency deviation ranges within which phase-locked loop-based circuits can achieve lock under various additional conditions. History In the classic books on phase-locked loop A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a ...s, published in 1966, such concepts as hold-in, pull-in, lock-in, and other frequency ranges for which PLL can achieve lock, were introduced. They are widely used nowadays (see, e.g. contemporary engineering literature and other publications). Usually in engineering literature only non-strict definitions are given for these concepts. Many years of using definitions based on the above concepts has led to the advice given in a handbook o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hidden Attractor
In the bifurcation theory, a bounded oscillation that is born without loss of stability of stationary set is called a hidden oscillation. In nonlinear control theory, the birth of a hidden oscillation in a time-invariant control system with bounded states means crossing a boundary, in the domain of the parameters, where local stability of the stationary states implies global stability (see, e.g. Kalman's conjecture). If a hidden oscillation (or a set of such hidden oscillations filling a compact subset of the phase space of the dynamical system) attracts all nearby oscillations, then it is called a hidden attractor. For a dynamical system with a unique equilibrium point that is globally attractive, the birth of a hidden attractor corresponds to a qualitative change in behaviour from monostability to bi-stability. In the general case, a dynamical system may turn out to be multistable and have coexisting local attractors in the phase space. While trivial attractors, i.e. stable equ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CP-PLL
Charge-pump phase-locked loop (CP-PLL) is a modification of phase-locked loop A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a ...s with phase-frequency detector and square waveform signals. CP-PLL allows for a quick lock of the phase of the incoming signal, achieving low steady state phase error. Phase-frequency detector (PFD) Phase-frequency detector (PFD) is triggered by the trailing edges of the reference (Ref) and controlled (VCO) signals. The output signal of PFD i(t) can have only three states: 0, +I_p, and -I_p. A trailing edge of the reference signal forces the PFD to switch to a higher state, unless it is already in the state +I_p. A trailing edge of the VCO signal forces the PFD to switch to a lower state, unless it is already in the state -I_p. If both trailing edges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kalman's Conjecture
Kalman's conjecture or Kalman problem is a disproved conjecture on absolute stability of nonlinear control system with one scalar nonlinearity, which belongs to the sector of linear stability. Kalman's conjecture is a strengthening of Aizerman's conjecture and is a special case of Markus–Yamabe conjecture. This conjecture was proven false but led to the (valid) sufficient criteria on absolute stability. Mathematical statement of Kalman's conjecture (Kalman problem) In 1957 R. E. Kalman in his paper stated the following: If ''f''(''e'') in Fig. 1 is replaced by constants ''K'' corresponding to all possible values of ''f'''(''e''), and it is found that the closed-loop system is stable for all such ''K'', then it intuitively clear that the system must be monostable; i.e., all transient solutions will converge to a unique, stable critical point. Kalman's statement can be reformulated in the following conjecture: Consider a system with one scalar nonlinearity'' : \fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1936 Births
Events January–February * January 20 – George V of the United Kingdom and the British Dominions and Emperor of India, dies at his Sandringham Estate. The Prince of Wales succeeds to the throne of the United Kingdom as King Edward VIII. * January 28 – Britain's King George V state funeral takes place in London and Windsor. He is buried at St George's Chapel, Windsor Castle * February 4 – Radium E (bismuth-210) becomes the first radioactive element to be made synthetically. * February 6 – The 1936 Winter Olympics, IV Olympic Winter Games open in Garmisch-Partenkirchen, Germany. * February 10–February 19, 19 – Second Italo-Ethiopian War: Battle of Amba Aradam – Italian forces gain a decisive tactical victory, effectively neutralizing the army of the Ethiopian Empire. * February 16 – 1936 Spanish general election: The left-wing Popular Front (Spain), Popular Front coalition takes a majority. * February 26 – February 26 Inci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Electrical Engineers
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
